The use of amine oxides as a detergent raw material is well established. Typical applications for this product group include foam boosters in liquid detergents, fragrance solubilisers and thickeners in various systems including thickened hypochlorite bleach cleaners. Alkyl-dimethylamine oxides, where the alkyl chain is generally of fatty origin and in the range of C.sub.8 -C.sub.22, are commonly used for detergent applications.
The synthesis of the amine oxides involves the oxidation of a tertiary amine, which is usually accomplished by reaction of the amine with hydrogen peroxide.
An issue with this product group has been the presence of residual raw materials, specifically unreacted residual amine and hydrogen peroxide.
Hydrogen peroxide can be particularly problematic. For example, in thickened hypochlorite bleach formulations, this can lead to reaction with sodium hypochlorite and subsequent decomposition resulting in the evolution of oxygen. This can cause formulations to foam, resulting in processing and packing difficulties. The residual hydrogen peroxide may also react unfavorably with dyes and perfumes often used in household and cosmetic formulations.
Residual tertiary amine may also create difficulties for the formulator. This is particularly true with respect to viscosity characteristics of formulations, as well as potential problems with odour and colour. Other unwanted by products may form when these products containing high levels of residual amine are used in certain formulations. Reduction of the residual level of amine will reduce the formation of these products.